摘要
某电厂高压加热器在检修过程中出现部分换热管泄漏,原封堵工艺采用实心0Cr18Ni9钢堵头及不锈钢焊条焊接,由于焊条与管板的钢种不同,膨胀系数差别较大,导致焊接堵漏产生裂纹。改进工艺后采用空心20号钢堵头及J422焊条焊接,堵头及焊条与管板的钢种相同,焊接堵漏后未再产生裂纹。通过有限元法应力分析表明,改进后的空心堵头所产生的焊接残余应力低于实心结构堵头。
The leakage of some heat-exchange tubes in high-pressure heater has appeared during repair process in one power plant.The solid Cr18Ni9 steel plug and stainless steel electrode were used in original plugging process,and cracks have occurred in weld-joints of leakage-plugging due to different materials of the electrode and the tube-plate,thereby,having larger difference in expansion coefficient.After improvement of the technology,the hollow plugs of no.20 steel and J422 electrode are used,the materials are similar to that of the tube-plate,and cracks haven't occurred after weld-plugging.The stress analysis using finite element method shows that the residual stress of welding with hollow plugs is lower than that of plugs with solid structure.
出处
《热力发电》
CAS
北大核心
2012年第8期69-71,共3页
Thermal Power Generation
关键词
高压加热器
换热管
泄漏
异种钢焊接
堵头
残余应力
high-pressure heater
heat exchange tube
welding of dissimilar steels
plug
residual stress
